Disappearance of minnows from Tahoe concerns scientists
By Jeff Delong, Reno Gazette-Journal
Lake Tahoe’s native minnows appear to be dropping significantly in number, with declining water clarity and predation by non-native warm water fish possible factors in the population crash.
Densities of minnows surveyed at 26 sites around the lake declined by 58 percent between 1988 and 2009, according to new research by scientists at University of Nevada, Reno and Ohio’s Miami University.
“That’s not good. That’s bad news,” said Sudeep Chandra, a UNR fisheries expert.
“I was surprised the decline was that much,” Chandra said. “The interesting question is what will be the future?”
Chandra and colleagues surveyed native fish populations in the shallow depths of Tahoe’s near shore, home to minnows such as Lahontan redside shiners and speckled dace.
Minnow numbers dropped significantly since the last such survey more than 20 years ago, with populations of redside shiners alone dropping between 24 percent and 100 percent in 42 percent of surveyed locations.
“I would say that yes, they are in trouble,” said Christine Ka Lai Ngai, another UNR researcher in the fish study. “And if we don’t do anything about it, they will be in more trouble.”
One possible contributor to the minnows’ decline is competition or predation by non-native warm water fish including largemouth bass and bluegill.